This application claims the benefit of the Korean Application No. P2002-0032902 filed on Jun. 12, 2002, which is hereby incorporated by reference.
1. Field of the Invention
The present invention relates to an operational method of a multi-air conditioner, and more particularly, to a method to compensate for refrigerant pressure of an indoor unit.
2. Discussion of the Related Art
Generally, air conditioner is an apparatus to cool/heat indoor space such as a residential space, office, restaurant and the like, and is provided with a compressor and a heat exchanger to flow refrigerant and thus cool/heat indoor air.
The development of the air conditioners is directed toward a multi-air conditioner capable of performing cooling and heating at the same time so as to maintain more pleasant indoor environment without being affected by external temperature and environment. As a result, it became possible to cool or heat an overall room at the same operation mode.
In these multi-air conditioners, a plurality of indoor units are connected to a single outdoor unit. Each indoor unit is installed in each room and is operated in either cooling mode or heating mode to control indoor temperature.
However, as the indoor structure becomes complicated, locations, uses and sizes of respective rooms are different and lengths and diameters of pipes connecting between the outdoor unit and the respective indoor units are also different, there is a limitation in cooling or heating the respective rooms uniformly.
In other words, the refrigerant flowing through an indoor unit arranged to be distant from the outdoor unit relative to other indoor unit(s), has a refrigerant pressure that is lower than the refrigerant pressure of other indoor unit due to a pressure drop. This indicates that the flow amount of the refrigerant is non-uniform, so that the cooling or heating efficiency of the distant indoor unit is lowered compared with other room(s).
Accordingly, the present invention is directed to a method for controlling an operation of a multi-air conditioner that substantially obviates one or more problems due to limitations and disadvantages of the related art.
An object of the present invention is to provide a method for controlling an operation of a multi-air conditioner in which each room can be sufficiently air-conditioned although lengths and diameters of pipes connecting between an indoor unit and respective outdoor units are different from each other.
Additional advantages, objects, and features of the invention will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention. The objectives and other advantages of the invention may be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.
To achieve these objects and other advantages and in accordance with the purpose of the invention, as embodied and broadly described herein, there is provided a method for controlling an operation of a multi-air conditioner. The method includes the steps of: compressing refrigerant by a compressor provided in an outdoor unit and discharging the compressed refrigerant; measuring, in a heating mode or a cooling mode, a pressure of the refrigerant flowing in or out a plurality of indoor heat exchangers and the compressor; and compensating the pressures of the refrigerant in the indoor heat exchangers in a prescribed pressure range.
In more detail, the step of measuring the pressures of the refrigerant flowing in or out the indoor heat exchangers comprises the step of measuring the pressures of the refrigerant in an inlet and outlet of each of the heat exchangers.
The step of compensating for the pressure comprises the steps of: comparing any one of the measured pressures of the refrigerant flowing in or out the indoor heat exchangers with the prescribed pressure and determining which one is greater than the other; and increasing a compressive force of the compressor according to the result of the comparison.
In more detail, the step of comparing pressures comprises the step of comparing the lowest pressure of the refrigerant flowing in or out the indoor heat exchangers or an average pressure of the pressures of the refrigerant flowing in or out the indoor heat exchangers side with the prescribed pressure.
Also, the step of compensating the pressure includes the steps of: comparing any one of differences between the pressures of the refrigerant flowing in or out the indoor heat exchangers and the pressure of the refrigerant flowing in or out the compressor with the prescribed pressure and determining which one is greater than the other; and increasing a compressive force of the compressor according to the result of the comparison.
The step of increasing the compressive force further includes step of gradually increasing the compressive force of the compressor by a variable compressor. Also, the compressor is preferably a variable compressor enabling to increase the compressive force depending on a variation in length or diameter of a connection pipe.
When the variation in load of the multi-air conditioner is large, an operation control method of a multi-air conditioner including a constant-speed compressor together with the variable compressor can be selected to increase the compressive force.
According to the aforementioned operational method of the invention, although lengths and diameters of pipes connecting between the respective indoor units are different, it is possible to sufficiently air-condition the respective rooms.
It is to be understood that both the foregoing general description and the following detailed description of the present invention are exemplary and explanatory and are intended to provide further explanation of the invention as claimed.